The three pillars of holiday party attire are sugar, spice, and all things nice. Guess which one Haley Bieber is leaning toward this season?

On December 7, the founder of Lorde supported the opening of Gigi Hadid's latest guest-in-residence boutique, presenting her with an evening outfit styled by Dani Michelle. She hunted down a vintage velvet skirt suit from the Saint Laurent archives, circa 2002. Bieber posed prettily in front of Hadid's winter cashmere hanger with a half-up, half-down hairstyle, a black velvet ribbon tied around her head, and a black sweater draped over her shoulders as a gift. But Bieber had plans for the evening that went beyond shopping at a friend's store.

Shortly after stopping by the store, the inventor of Peppermint Glaze Treatments enjoyed dinner with Kylie Jenner at Los Angeles hot spot Wally's. The dress code for their girls' night out was to ditch the sweater Bieber wore to Hadid's grand opening party. Instead of slinging the sweater over her shoulder, she pulled off a red-hot styling hack: she stopped wearing a shirt under her blazer.

The cheerful red holiday outfit is Bieber's most recent uniform. A few days earlier, she wore a micro-mini red dress and a fluffy fur coat to promote her latest rodeo gift set.

Bieber's shirtless suit may be a bit NSFWP (dangerous for a workplace party), but it can fly for an intimate dinner or white elephant gift exchange with friends. Of course, we'll take advice from the Rhode Island native Bieber himself: a sweater over the jacket below will change the whole vibe.